Power transmission



Nov. 9, 1943.

c. A; NERACHER ETAL 2,333,668

POWER TRANSMISSION Filed Oct. 16, 1939 11 Sheets-Sheet l NV 9, 1943. c. A. NERACHER ETAL 2,333,668

POWER TRANSMISSION Filed Oct. 16, 1939 l1 Sheets-Sheet 2 NOV- 9, 1943. c. A. NERAcHr-:R ETAL 2,333,658

PQWER TRANSMISSION Filed 001i. 16. 1939 l1 Sheets-Sheet 3 Nov. 9, 1943. c. A. NERACHER Erm. 2,333,668

POWER TRANSMISSION Filed 06T.. 16, V1939 11 Sheets-Sheet 4 Nov. 9, 1943.

POWER TRANSMISSION Filed Oct. 16, 1939 1l Sheets-Sheet 5 [N VE N TORS- c f w m a MM5@ 4 55 u NOV- 9, 1943. c. A. NERACHER Erm. 2,333,658

POWER TRANSMISS ION Filed Oct. 16, 1939 1l Sheets-Sheet 6 E; N@ A f' "j M m, MM40@ TTORNE Ys.

N0V- 9 1943. c. A. NERAcHER ETAL 2,333,668

POWER TRANSMISS ION Filed oct. 1e, 1939 11 sheets-sheet 7 2?'7 flag j NOV, 9, 1943, c. A. NERACHER ETAL 2,333,658

POWER TRANSMISSION Filed 001i. 16, 1939 11 Sheets-Sheet 8 W @ZM/j@ TTORNE ya NOV- 9, 1943. c. A.' NERACHER ETAL 2,333,658

POWER TRANSMISSION Filed Oct. 16, 1939 11 Sheets-Sheet 9 .l Hayes Nov. 9, 1943. c. A. NERACHER Erm.

POWER TRANSMISSION Filed Oct. 16, 1939 l1 Sheets-Sheet 10 N0 9, l1943. c. A. NERACHER ETAL 2,333,668

POWER TRANSMI S S ION Filed Oct. 16, 19259 11 Sheets-Sheet ll @L y E .En

4Patented Nov.` 9, 1943 `UNITED- sTATEs PATENT oFFlcE POWER TRANSMISSION Carl A. Nera/cher, William T. Dunn, Teno Iavelli,

and Augustin J. Syrovy,Detroit, Mich., assignors to Chrysler Corporation, Highland Park, Mich., a corporation of Delaware .j

Application october 16, i939, serial No. 299,674

4s claims. (ci. 'za-472) positively engaging clutch means having synchronous control for insuring clutching without shock or ratcheting noise.

A further object is to provide an improved system of vehicle drive incorporating both manual and automatic change speed control affording improved vehicle driving functions.

A still further object is to provide an improved pressure lubrication system that is contained entirely within the transmission casing.

We have provided an improved drive system incorporating a -uid coupling and kickdown transmission so constructed as to provide great :flexibility of car control with very little eil'ort such that'nearly all driving may be done without manipulation of clutch pedals or gear shift levers and at the same time affording flexibility of car control best suited to the changing requirements of torque multiplication and other power transmitting characteristics. Our driving mechanism affords improved quietness and smoothness of car-operation and facilitates manipulation of the car especially under heavy trame conditions.

We preferably employ a relatively fast axle such that, when the transmission is in direct, the overall drive is the practical equivalent of an overdrive without driving through gear trains at such time. Thisis practicably obtainable without sacrificing car performance by our improved synchronous clutching means which automati. cally responds to manipulation ofthe accelerator pedal for stepping the speed ratio up or down.

With our transmission it is practicable for the driver to stay in a selected speed ratio setting while stopping, and thereafter obtain rapid car starting acceilerations under favorable torque' multiplication, and faster ratio boulevard or country drive conditions without operating the clutch pedal or the gear shift lever.

We have provided a manual selection of high and low ranges in our transmission, but in most instances the low range is in the nature of an emergency low and when the uid coupling is employed very desirable car accelerating characteristics are obtained by manual selection vof the high range.

According to the present embodiment of our invention, we have provided a transmission employing a countershaft and a planetary gearing and providing four forward speeds and reverse. Manual selection of the countershaft gearing may be made to high and low ranges, in each of' which an automatic shift. in the planetary gearing occurs to a faster drive ratio and back to the selected range, the automatic shifting being effected by natural functional manipulation of the accelerator pedal.

In one embodiment of our invention we have provided a speed responsive control on the automatic shift means controlling this shift in a novel manner.

Additional features of our invention are found in the provision of a simplied remote shift mechanism for the manual control; an improved `control for preventing undesired lock-up in the parts which might cause a no-back condition; and many features of construction and functional operation which will be more apparent from the following illustrative embodiments of the principles of our invention, reference being had to the accompanying drawings, in which:

Fig. 1 is a side elevational view of the power plant and transmission for a motor vehicle.

Fig. 2 is a plan view somewhat diagrammatically illustrating the power transmission assembly in relation to the vehicle driving ground wheels.

Fig. 3 is a sectional view of the remote control hand shift mechanism taken as indicated by line 3-3 of Fig. 1.

Fig. 4 is a top plan view of the Fig. 3 mechalnism taken as indicated by line 4-4 of Fig. 1.

Fig. 5 is a sectional viewalong line 5-5 of Fig. 1 showing a portion of the remote control shift.

Fig. 6 is a detail sectional view taken as indicated by line 6-8 of Fig. 5.

Fig. 7 is a detail sectional elevational view of a portion of the' engine throttle operating mechanism shown in'` Fig. 1.

Fig. 8 is an enlarged side view partly in section and partly in elevation showing the Fig. 1 power transmission.

Fig. 9 is a sectional elevational view through the speed ratio changing transmission which is illustrated in elevation in Fig. 8.

Fig. 9A is a detail elevational view of the reverse idler and associated gears of the Fig. 9 transmission.

- rearwardly as indicated by line Ill- I of Fig. 8,

showing the transmission portion of the remote shift mechanism.

Fig. 11 is a detail-sectional view taken as indicated by line l I-I I of Fig. 10.

Fig. 12 is a sectional plan view taken as indicated by line |2-l2 of Fig. 9,

Fig. 13 is a detail sectional view taken as indicad by line I3-l3 of Fig. 8.

Fig. 14 is a detail sectional view taken as indicated byline IB-H of'Fig. 8.

Fig. 15 is a detail sectional plan view taken as indicated by line I-I5 of Fig. 8.

Fig. 16 is a detail taken `as indicated by the line |6--I6 of Fig. 15 and showing the control valve in kickdown position.

Fig. 17 is a detail sectional view taken as indicated by the line l1-l1 of Fig. 15.

Fig. 18 is a detail sectional view taken as indicated by the line |8-l8 of Fig. 9.

Fig. 19 is a detail sectional view of the kickdown shift mechanism taken as indicated by the line |9-l9 of Fig. 18.

Fig. 20 is a detailed sectional view taken as indicated by the line 20-20 of Fig. 18.

Fig. 21 is an enlarged sectional view of the iiuid pressure control switch taken as indicated by the line 2|-2I of Fig. 19.

Fig. 22 is a detail sectional View looking rearwardly of the transmission taken as indicated by the line 22--22 of Fig. 9.

Fig. 23 is a detail sectional view of the synchronous blocker clutch mechanism taken as indicated by the line 23-23 of Fig. 9.

Fig. 24 is a diagrammatic view of the transmission control system.

Fig. 2'4A is. a. sectional view on an enlarged scale of the pedal operated switch L of Figs. 1 and 24.

Fig. 25 is an enlarged diagrammatic view of the governor switch mechanism of Fig. 24.

Fig. 26 is a diagrammatic view of a portion of the Fig. 24 diagram illustrating a modified control arrangement.

Fig. 27 is a fragmentary sectional view of a modified form o'f the invention.

Fig. 28 is a sectional view along line 28-25 of Fig. 27.

Fig. 29 is a fragmentary sectional view of a further modication.

Fig. 30 is a sectional view along line 3-3 of Fig. 29, and

Fig. 31 is a sectional View along line 3l--3l of Fig. 29.

We have illustrated the principles of our invention in connection with a motor vehicle drive wherein the usual'engine A transmits its drive through clutching means B, C, within casing 50,

' the drive then passing through the change speed transmission D and propeller shaft 5l (Fig. 2) to the differential 52 and thence to the vehicle ground wheels 53 where it is desired to drive the rear wheels according to present day practice.

By preference, the arrangement is such that a faster rear axle ratio is afforded than is generally customary so that when the transmission is in direct drive, the car is driven in the equivalent of an overdrive ratio between the engine A and wheels 53. Our arrangement provides such conveniently operable kickdown or shift to a reduction drive from direct that the aforesaid arrangement is practicable thereby obtaining advantages of economy, long life and quietness of operation without the disadvantages of sluggish operation which is especially objectionable in city driving.

The engine A has the customary intake mani- -fold 54 and the carburetor riser 55 containing a.

throttle valve 56 operable by a lever 51 throughout a range between the illustrated closed throttle position for engine idling and a wide open position limited by lever 51 engaging a stop 58. Lever 51 is adjusted by a driver operable accelerator pedal 59 pivotally mounted at 60 on the toeboard 6| to swing downwardly against restoring spring62 to thrust through the system of pivotally jointed links B3, 64 and connecting lever 65, the latter being pivotally supported at 66.

The link Blioperates lever 51 through a lost motion'device (Fig. '7) serving to normally connect these parts as a solid member but aording thrust of link 64 forwardly after lever 51 has engaged its limiting stop 58 to effect the kickdown control on the transmission. Thus, link 6B has its forward end slidable in guide 61 of finger 68 which is pivoted to the lower end of lever 51. A spring 69 ,acts between finger 68 and a collar 1B fast on link 64 and yields only when link 64 is thrust forwardly after lever 51 has engaged stop 58, the spring otherwise transmitting thrust of link 64 to finger 68 without lost motion. A bracket 1l limits separation between the link 68 and finger 68 and closes the throttle valve 55 when the accelerator pedal is released for upward swing -by spring 62.

The throttle operating mechanism therefore is such that movement of pedal 59 throughout its normal range will cause a corresponding adjustment in the valve 56 between its limits of fully closed and wide open positions. When the pedal has been depressed to the wide open throttle position, lever 51 engages stop 58 and further depression of the pedal in its kickdown range of movement for the kickdown transmission control is accommodated by yielding of spring 69 while the throttle valve remains fully open. On release of the accelerator pedal. springs 59 and 52 both act until collar ill engages the rear flange 12 of bracket 1I and thereafter, throughout the normal range of throttle adjustment, spring 52 alone serves to restore pedal 55 and close the throttle valve.

The kickdown range of accelerator pedal movement is utilized to momentarily unload the engine of its drive, as by shorting the ignition, and to effect disengagement of the synchronous clutch sleeve for a change in the transmission from direct to underdrive accommodated by unloading the clutch sleeve of the engine drive. The throttle being open will cause the engine to rapidly speed up as soon as the ignition circuit is restored, the underdrive being automatically eiective as will presently be more apparent.

The lever 65 has fastened thereto a second lever 13 directed forwardly to provide spaced fingers 1li, 15 in the path of the actuator 16 of the snap-switch 11 which is a control part of the kickdown mechanism. When pedal 59 moves in its kickdown range, finger 15 throws actuator 1B 'rearwardly to close switch 11, the switch remaining closed until the pedal 59 is fully released, or substantially so, at which time nger 14 restores actuator 16 to the Fig. 1 position to open the switch 11. The ignition circuit, after interruption during-kickdown, is not dependent for restoration on release of the pedal 59 but isV restored by other means presently described.

We preferably transmit the drive from the engine A to transmission D through clutch means comprising a-fluid coupling B of the kinetic type v ter starting) or where the throttle is accidentally opened.

The engine crankshaft 18 drives the coupling impeller`19 to circulate the fluid in its vaned passages to drive the vaned runner 80 in a manner well known for fiuid couplings of the type illusvtrated. 'Ihe runner 80 drives the clutch member 8| of the friction clutch C of commercial design.

lDriven clutch-disc 82 is xed to intermediate drive shaft 83 and is drivingly disengaged by depressing a clutch pedal 84 (Fig. 1) which slides the throw-out member 85 forwardly to operate levers 86 to unload driving pressure plate 81, springs 88 loading this plate and engaging the clutch when pedal 84 is released.

Shaft 83 extends rearwardly into the housing 89 of transmission D (Fig. 9) where it is formed with a main drive pinion 90 and a set of external driving teeth I| which are adapted to slidably engage internal clutch teeth |02 of the synchronous coupling clutcl'r sleeve Q. Fixed to the shaft 93 is a hub |04 formed with external teeth |05 slidably engaged with the internal teeth |02 of the shiftable clutch sleeve Q which is adapted to be shifted forwardly or rearwardly by a -fork ||2 fixed to a longitudinally extending shift rail ||3 (Fig. 10) disposed on the left side of shaft 93 (looking forwardly of the vehicle).

The drive pinion 90 is hollow and journals, by a bearing 92, the forward end of the intermediate transmission driven shaft 93 which is adapted to drive the secondary or tail-shaft |03. The latter may carry a propeller shaft brake drum 94 having the braking mechanism generally designated at 95 operably associated therewith. The drive pinion 90 is continuously meshed with a gear 96 for driving the countershaft cluster 91 rotatable on a countershaft support 98.

The cluster 91 also includes a gear |01 which drives a pump P (Figs. 9, and l2). The pump P develops the fluid pressure necessary to the operation of the automatic phase ofthe transmission and for lubrication thereof and is of the well known Gerotor type having an inner driving member |23 and an outer driven member |24 defining intake and delivery chambers |25 and |26, respectively. The driving member |23 is secured to a shaft |21 rotatablev in a stationary pump housing |28 closed by a cover |29 at its outer end. 'I'he upper end of shaft |21 carries a gear |30 which meshes with the pump drive gear |01 of the countershaft cluster 91.

The intake of suction chamber |25 receives a constant supply of oil through an inlet passage |3| which opens into the oil reservoir or pump |32 along the bottom of the transmission casing 89. The oil under pressure is delivered from the pump pressure chamber |26 rearwardly through the delivery passage |31 which is in communication with the main control valve V (Figs. 13, 15 and 16). The valve V controls the fluid pressure motor M (Fig. 19) as well as the lubrication oil pressure of the transmission as will be explained later on in this specification.

The cluster 91 is further formed with gears |06 and |08. Gear |06 is in constant mesh with a gear |09 which is freely journalled on driven shaft 93. 'I'he reverse gear |08 is adapted to mesh with an idler gear ||8 (Fig. 9A) when the idler ||8 is also meshed'with aigear |2| xed on shaftl93. t

A pair of synchronizing blocker rings ||4, ||5

are respectively disposed between the hub `|04 and gears 90 and |09 and are driven .with hub |04 with slight rotational clearance. These blockers have cammed teeth H6, ||1 having a i pitch circle the same as that of sleeve teeth |02 and teeth |0| and ||0, and they are adapted to frictionally engage the cone-shaped clutching surfaces rH0' and respectively. If desired, energizing springs |22 may be provided between the blockers to lightly urge them into engagement with cones H0' and respectively so that the blocker teeth H6, ||1, are misaligned with the sleeve teeth |02 thereby preventing shift of sleeve Q as long as the parts to be clutched are rotating. at different speeds. The synchronizing blocker rings are more fully described and claimed in the copending application of O. E. Fishburn, Serial No. 180,840, filed December 20, 1937.

When sleeve Q is moved forwardly, teeth 02 engage the cammed ends of blocker teeth 6 thereby urging the blocker under pressure into engagement with the cone-shaped clutch surface ||0' to synchronize gear 90 with shaft 93 (clutch C being released during manual shift of sleeve Q to facilitate this clutching action). The blocker 4 will then rotate slightly relative to hub |04 to permit the sleeve teeth |02 to pass through blocker teeth ||6 to engage teeth |0| thereby positively clutching shaftv 93 with gear 90. The

rearward shift of sleeve Q to clutch with teeth s shift rail |38 parallel to and below rail ||3. The

fork |20 engages the hub portion |39 of the shiftable reverse idler gear I8. Rails ||3 and |38 are interloeked by a plunger |40 to prevent the simultaneous displacement.

Lever |34 is supported between its ends by a pin |4| parallel to and above rail 3, this pin being carried by the yoked inner end |42 of shaft |43 rotatably mounted in the boss |44 of cover |45 which is secured by fasteners |46 to casing 89.

.. The shaft |43 has its axis extending across the axis of movement of the rails I3 and |38 and has a lever |41 xed to its other end outside of the cover |45. A spring |48 reacts-on shaft |43 and yieldingly urges lever |34 clockwise (Fig. 10) about pin |4| tending to maintain pin |33 engaged in slot |32 and end |35 free from slot |36. A spring-pressed ball detent |49 (Fig. 15) yieldingly maintains rail I3 in neutral, forwardly (to clutch sleeve Q with teeth |0|), or rearwardly (to clutch sleeve Q with teeth I0) by engagement of. this ball detent by the rail recesses |50, |5| and |52, respectively. 'Ihe reverse rail |38 has neutral and reverse positioning recesses |53, |54 respectively engaged selectively by a spring-pressed ball (notshown).

A switch R (Figs. 11 and 15) is fastened to the cover and is positioned inside the transmission casing in such manner that the plunger 360 thereof will be engaged `by the enlarged portion H3' on the forward end of the shifter rail ||3 when said rail is in neutral position. The purpose of switch R will be explained further on in this specication.

The upper end of lever |34 has a wide face |56 engageable with the inner end of aplunger |51 slidable inwardly through cover |45 by a Bowden wire operating mechanism |58. When the wire |58 is pushed, the plunger |51 engages lever face |56 to swing the lever |34 so thatA the end |35 engages slot |36 while pin |33 disengages slot |32. In such position the shaft |43 may be rotated to shift rail |38 to mesh reverse idler I8 with gears |08 and |2| for reverse drive. The plunger |51 maintains a sliding engagement with lever face |56 during this rotation of shaft |43. The remote control mechanism for effecting control of lever |41 and Bowden wire |58 will not be described (Figs. 1 and 3 to 6). The fixed steering post I 59 houses the usual steering shaft |60 operated by hand steering wheel |6|. Rotatably assembly |62 connected by pivot pins |63 with the yoked inner end |64 of the manually operable selector element of shift lever |65 which extends outwardly through an arcuate opening operates to yieldingly urge plunger |1| into engagement with the lower surface of portion |10 and to maintain plunger |51 free of engagement with leverY face |56 as shown in Fig. 10. A link |13 has its forward end pivotally engaged with the outer end of the lever |69, the rearward end of this lever being connected to a bell crank lever |14 mounted on engine A at |15. The bell crank operates a second link |16 which has articulated connection with lever 41.

|66 formed in the head |61 fixed to post |59. Movejournalled within the post |59 is a hollow shaft g In order to shift sleeve Q into engagement with sliding rail ||3 and sleeve Q forwardly to clutchV with the teeth |0| of'gear 90 to establish direct drive between-shafts 83 and 93.- As will be explained later on, this latter operation of the lever establishes a third speed ratio of the four available forward speeds.

In order to effect the reverse drive, the lever |65 is first Arocked upwardly about the fulcrum |68 to thereby push shaft |65 downwardly to cause lever portion |10 to operate through the Bowden wire |58 to swing |34 counterclockwise about the shaft |4| thereby engaging the end |35 with slot |36 of fork |20 and disengaging pin |33 from engagement'with the slot |32 of the boss |3|. Thelever |65 is then shifted rearwardly 4or clockwise of the steering column to cause lever'l41 to rock lever |34 forwardly to idler gear I8 with gears |08 and |2| The clutch C is preferably released during this manual shift of sleeve Q and reverse idler H8.

From the foregoing it will be apparent that drive from the engine crankshaft 18 may be transmitted through the fluid coupling B and clutch C to the driven shaft 93 which may be driven at the speed of the shaft 83 and in the same direction; at a reduced speed and in the same direction with respect thereto; or at a reduced speed in a reverse direction with respect thereto. v

Referring now again to Fig. 9, it will be seen that the shaft 99 terminates at its rearward end in an enlarged hollow portion|15 into which the forward end of the tail shaft |03 is piloted by means of a bushing |16. 'I'he shoulder |11 is provided to receive the inner race ofan antifriction bearing |18, the outer race of which is received in a complementary recess formed in the member |19 which forms the rear wall of the casing 89.

A casing is fastenedv to the casing 89 by means of the fastening screws |8| and houses the planetary gearset G and its associated mechanism which constitutes the automatic phase of the transmission. A passage |80 permits the oil in the sump of casing |80 to circulate through the sump |32.

The rearward end of the tail shaft |03 is supported at the rear end of the casing |89 through the bearing |82 and a suitable sealing device |83 is provided between the rear cap member |84 and the shaft |08 to prevent leakage of the lubricating oil on to the brake drum 94.

The rearward end of the shaft 93 is further enlarged rearwardly of the bearing |18 and is formed with an annulus gear |85 having internal teeth which mesh with a plurality of planet gears or pinions |86, each planet gear being rotatably mounted on an axle shaft |81 supported by a carrier structure |88 which has a forwardly extending 4hub portion |89 which extends within the hollow intermediate portion of shaft 93 and is splined at |99 to the tail shaft |03.

The planet gears |88 also mesh with the hollow sun gear |9| which is-loosely journalled on the shaft |09 and has a rearwardly extending controlling portion or sleeve |92 provided with clutch teeth |98 at its extreme rearward end.

It will thus be apparent that drive from the shaft 93 may be transmitted through the annulus A gear |85 to the carrier |88 and, if the sun gear eifect'forward shift ofrail |38 thereby meshing 75 |9| is held against the tendency to rotate backwardly (counterclockwise when looking from front to rear) when the shaft 93 rotates forwardly (clockwise), then the annulus gear |85 will operate through the planet gears |86 to transmit an underdrive to the tail shaft |03 relative to the speed of rotation of the shaft 93 by virtue of the carrier |88 driving through the splines |90 on the tail shaft |08. During this condition of Aoperation, the sun gear |9| which is loosely journalled on the shaft |03 has a tendency to rotate backwardly and must -be held against such rotation to provide for reaction of the underdrive. The means for holdingthe sun gear against counterclockwise rotation consists of a reaction taking or brake member |94 which is yieldably secured to the transmission casing |80 by means of a pair of diametrically oppositely located parallelly disposed pins |95 (Fig. 14),. At each side thereof, the casing |80 is provided with a boss |96 which has a bore surrounding the pin |95. This bore-is enlarged at the outer portion thereof adapted to bear against an annular washer |98 rigidly attached to the outer 'end of pin |95. A 'cap member |99 is threadedly received bythe casing |90 as indicated in Fig. 14 and provides for adjustment of the pressure of the spring |91.

In Fig. 14, the forward direction of rotation of shaft |03 is indicated by the arrow. It should be noted lthat a counterclockwise direction is indicated which is opposite to that indicated in Figs. 22, 23 which illustrate the positively acting clutch mechanism for locking up the planetary gearset-G. By referring to Figs. Sand 9 it will be seen that Fig. 14 looks from rear to front of the transmission, while Figs. 22, '23 look from front to rear, these directions having been chosen in order to fully illustrate the apparatus.

The reaction taking member |94 is provided at each end thereof with a pair of diametrically oppositely located notches 200 which receive the inner ends of the pins |95.

The reaction of the sun gear |9| is transmitted to the reaction member |94 by means of the rollers 20| which form part of `an overrunning clutch designated generally by the letter E. 'I'he rollers 20| are adapted to lock the control sleeve |92 of the sun gear 9| to the reaction member |94 upon tendency of the sun gear to rotate backwardly (or counterclockwise as viewed in Fig. 22). The locking action is accomplished automatically in the manner known in the art, the member |92 having a. cammedouter surface 202, the Acams being so formed that the rollers 20| are automatically locked between the cams and the inner cylindrical surface of the member |94 upon tendency of the member |92 to rotate backwardlv. Upon rotation of the member |92 in a forward direction (or clockwise as seen in Fig. 22) the rollers 20| are in contact with the low portion of the cams and the member I 92 is automatically released from the reaction member |94 as will be presently described.

In the event that the sun gear |9|- is directly drivingly connected with' one of the other elements of the planetary train, then the entire train will be locked to cause the gearing to rotate as a unit and transmit a direct drive from the shaft 93 to the tail shaft |03. We have provided means for locking the sun gear |9| to the shaft 03 for rotation therewith, and, under such conditions, the sun gear |9| will rotate in a for.- ward direction and will overrun the reaction I member |94 as will be permitted by the overrunning device E. i

The means provided to lock the sun gear to the shaft |03 is automatically opera-ble under control of the vehicle driver and comprises a longitudinally shiftable clutch member K having a set of external teeth 203 adapted to mesh with the internal teeth |93 provided on the rearward end of the sun gear control sleeve |92. 'I'he clutch member K is splined on the shaft |03 at 204 and is adapted to be shifted -by a shift yoke 205 as will be hereinafter explained.

As can be seen from Figs; 22 and 23, taken in conjunction with Fig. 9, the control sleeve l|92 is also provided with an internal cam 206 which forms one member of a second overrunning device F, the roller cage 201 of which is integrally connected to the cage 208' of the outer overrunning device E by a plurality of legs or spokes 209 as illustrated in Fig. 14. The second member of the cverrunning device F consists of' a blocker member 2|0 loosely splined on the shaft |03 as indicated at 2||. A coil spring 2|2 fas- |03 as shown in F1522 acts to yieldingly I'Otate the blocker rearwardly so as to engage the enlarged internal/splines of the block against one side of the mating splines on shaft |03.

The blocker 2|0 has a pair of diametrically oppositely located, rearwardly projecting lugs or pins 2|3 which are adapted under certain conditions of operation to be received into recesses 2|4 provided in the forward face of the clutch member K. Under ordinary driving conditions in underdrive, the spring 2 I 2 maintains the blocker member 2|0 in the position shown in Fig. 23. In this position the blocker 2|0 is rotated rearwardlyl on the shaft |03 as-far as the clearance around the splines 2|| will permit, and the lugs 2| 3 are so disposed on the. blocker with respect to the splines. that they will engage the forward face' of the clutch member K at points misaligned with the recesses 2|4 as illustrated in Fig. 23. Under such conditions, forward movement of the clutch member K, under the iniiuence of the shift yoke 205, will be prevented.

Rearwardly of the member K on-shaft |03 is mounted a worm wheel 99 which drivingly engages a worm |00 mounted on a shaft |00b, the

'against the bracket 2| 9,

latter constituting the speedometer drive for the vehicle speedometer.

The automatic control for the clutch member K will now be described. As aforesaid,-the clutch member K has a shifting groove engaged by the shift yoke 205 which extends downwardy and outwardly (Figs. 18 and 19,) in the casing |80 and then rearwardly in the form of arbar 2| 5, the end of which is bent inwardly at shoulder 2| l to slidably receive a shift rod 2|8. This shift4 rod extends longitudinally of the transmission and is guided for reciprocation in the casing by the bracket 2|9. The rod also slidably extends through the yoke 205 at 2I6. 'I'he rod 2|8 is grooved at 220 to receive an abutment snap ring 22|, a compression spring 222 acting between this ring and the yoke shoulder 2|1. A stronger spring 224 disposed within the bore 224' acts between the end of said bore and an abutment collar 225 xed to the forward end of the rod 2|8 and serves to yieldingly thrust the rod together with the yoke 205 and the clutch member K rearwardly to Fig. 19 position. The yoke 205 is limited in its forward movement relative to the rod 2|8 by the abutment ring 223 which is fixed in a suitable groove in the rod 2|8 as illustrated in Fig. 19. Forward movement of the rod 2|0 is limited by abutment of the ring 223 the rod being capable of forward movement in advance of forward shift of the yoke 205 and clutch member K.

Forward shift of rod 2| 8 is effected by prime mover means preferably in the form of a pressure fluid motor M which comprises a cylinder 226 slidably receiving a piston221 fixed on the rearward end of rod 2 |8. The cylinder head consists of the casing of a switch 'S which threadedly engages the cylinder, the function of which will be made apparent lateron in the specication. The switch casing S limits rearward movement of the piston and rod under the action of the spring 224. Pressure'uid, preferably oil, is admitted to cylinder 226 in rear of piston 221 through the communicating delivery passages 228 and 229.

The passage 229 extends longitudinally of the transmission housing as shown im Figs. 13, 14, 15 and 20 and communicates with the pressure port 233 of the valve V (Figs. 15 and. 16). 'I'he a tened to the blocker member and to the shaftl delivers the pressure fluid into the passage |31 from which the oil flows through the passages 238 and 23|l (Fig. 3) which extends respectively transversely and upwardly of the casing 89. The passage 23| communicates directly with the intake port 234 of the valve V as shown in Figs. 13,

. l and 16, thus assuring a constant supply of oil under pressure in the chamber 236 of the valve V at all times when the shaft 83 is rotating.

Besides serving as a control means for the motor M,-valve V also regulates the lubrication pressure of the entire transmission. As willl be seen from Figs. 15 and 16, the bore or chamber 235 of the valve V is adapted to receive the stem 236 and piston 231, the latter being urged forwardly by a spring 238 housed in the rearward end of said bore. The stem 236 is adapted to abut the piston 231, but is unconnected thereto, and has av pair of enlarged portions 239 and 248 formed integrally therewith, the latter having a plurality of openings 24| which permit the pressure uid in chamber 235 to impinge upon .the forward end of the piston 231 regardless ofthe position of the stem 236, The lubricating portion 242 of the valve V communicates with a passage 243 (Figs. 13 and 16) which in turn communicates with a lubricating slip ring 244 through the pipe 245. The lubricating slip ring 244 has an internal groove 246 formed on its inner periphery. A

plurality of passages 241 (Fig. 13) establish communication between the groove 246 and an annular chamber 248 formed by a bushing 269 which surrounds the shaft 93 adjacent the bearing |18'. The chamber 248 communicates through va passage 258 with the axial bore 25| of the shaft 93 which permits lubricating oil to be distributed rearwardly tothe planetary gearset G, the overrunning devices E, F, etc. Suitable oil holes, suh as 252 are provided to facilitate distribution of the oil to all of the parts to be lubricated.

The spring 238 forms the pressure regulating means for the lubrication system of the transmission and limits the pressure developed by the pump P. 'Any suitable size of spring may be used to suit various conditions, a spring of approximately 45 lbs. pressure having been found satisfactory.

As aforesaid, there is a constant supply of oil under pressure in the chamber 235 of valve V at all times when shaft 83 is rotating. Under such conditions piston 231 will be maintained by the oil pressure in a rearward position against the spring 238 by the uid impinging thereon and port 242 of the valve will be uncovered. The fluid also impinges on the enlarged portion 239 of the stem 236 thus maintaining the stem in forward (open) position as illustrated in Fig. 15. Pressure port 233 is thus normally open and the pressure fluid entering chamber 235 through port 234 flows unrestricted through passage 229 and into cylinder 226 (Fig. 20)

l)Assuming that the vehicle is driven in underdrive with the sun gear |9| locked to the casing |88 by action of the overrunning device E; as

Under this condition of operation switch S is maintained by fluid pressure in the position shown in Fig. 21 even though the rod 2|8 has moved out of contact with the plunger thereof. The switch S comprises a casing 255 formed with a neck 256 threaded for mounting in the rear end of the cylinder 226. The casing contains the insulating becly 251 carrying terminals 258, 258 and movable contacts 268, 26|. The latter are in electrical contact respectively with the terminals 258, 259, and are in the form of plungers urged radially inwardly of the body 251 by the coil springs 262, 263. Switch S further comprises a plunger 264 having a reduced forward portion 265 and aninsulating rear end portion 266. A coil spring 261 disposed between the latter and the rear end of the bore 263 provided in insulating body 251 urges the plunger 264 forwardly.

A contact ring 269 is fixed in a suitable groove in the insulating portion 266 and serves to close the switch by connecting contacts 260, 26| upon movementI thereof in either direction past said contacts.

Switch S is normally maintained open (asin Fig. 21) by either of two means, viz., the pressure fluid in cylinder 226 which contacts the plunger 264 through the clearance 218 provided between the reduced portion 265 and an annular ring 21| which is xed to the casing 255; or by the rod 2|8 which contacts the portion 265 of the plunger when at the end of its rearward stroke as shown in Fig. 2l. The switch S is in series with the klckdown switch 11 and, as will be presently apparent, functions to momentarily ground the engine ignition system to secure the reversal of engine *torque necessary to facilitate kickdown movement of the clutch member K.

Referring to Figs. 9, 18 and 25, the shaft |881) drives a flexible cable of the type known in the art and commonly used for driving vehicle .fspeedometera Intermediate the hpusing |80 and the speedometer (not shown) the cable |55 passes through the housing 212 of a governor Aswitch mechanism H. The housing 212 may be fixed to the vehicle floorboards, the dash, or any other convenient place and has journalled therein a shaft 213 on which is xed a driven gear 214 in mesh with the drive gear 215 mounted for rotation by the cable |55. The opposite end of shaft 213 carries the gear 216 which meshes with the gear 211 for driving the speedometer-end |16 of the cable.

Fixed to shaft 213 is a collar 218 of a governor 219 of the well-known iiyball type which operates the sliding collar 280 toward collar 218 as the weights ily outward under the influence of centrifugal force. Pivotally mounted to the cas- `ing at 28| is a lever having arms 282 and 283.

soon as the pump P develops sufficient pressure to overcome the combined pressures of the springs 222 and 226, the rod 2|8 (Fig. 19) will bev moved forwardly by the piston 221 until the ring 223 contacts the bracket 219. Loading of the spring 222 will of course tend to cause forward movement of the shift yoke 285 and clutch member K which action is prevented, during acceleration of the car in underdrive, by the blocker 2|8 as described previously.

Lever arm 282 has its free end in collar 288 while the arrangement is such that this contactor is governor mechanism H is driven from the tail shaft |03.

The nger 285 is so proportioned that at a relatively high car speed, say 55 or 60 M. P. H., this finger will in similar manner raise switch piece 289 away from fixed switch piece 290 of the high speed control'switch Y. As the car accelerates from rest, the switch`X therefore rst opens at a speed of approximately M. P. H. car speed and stays open above this speed. When the car reaches approximately 55 M. P. H. then the 'switch Y opens to break the kickdown circuit and thereby render the kickdown mechanism inoperative.

'Ihe above will be clear from Fig.v24 which is a wiring diagram of the transmission.

In Fig. 24, the vehicle battery is designated by the numeral 300 and is grounded4 to the frame at 'I'he other side of the battery is connected to the starting motor terminal 302 -and a wire 303 .connects this terminal to one side of the vehicle ammeter 304.y The other side of the ammeter is connected with the ignition switch 306 by wire 305. The other side of the ignition switch is connected to the ignition coil 301 through wires 308 and 309, the former having a branch 3|0 connected to the coil of a relay N. The latter controls the solenoid J and may be energized by several diierent connections to a ground. Upon energization of the relay N by any one of the several means about to be described, the movable contact piece 3|I is moved into electrical contact with thexed contact piece 3|-2 thereby connecting the coil of solenoid J with the battery 300 through wires 3|3 and 3|4.

'I'he other side of the solenoid J 'is grounded at A wire 3| 5 connects the coil of relay N with one side of the switch R, the other side of the switch being connected through wire 3| 6 to the xed contact piece 290 of the high speed governor controlled' switch Y, the movable contact 289 of which is connected by wires 3|1 and 3|1a with the kickdown switch 11, the latter being grounded at 3|9. A Wire 3|1b connects wire 3|1 with one side of a dash controlled switch 3|8, the other side of this switch being connected by wire 320 with thexed contact 281 of the low speed governor controlled switch X, the movable contact of which is grounded at 288. Switch 3|8 is also connected by wire 32| withl one side of the switch S which, as aforesaid, functions to momentarily ground the ignition upon kickdown manipulation of switch 11. As illustrated in Fig. 24,the other side of switch S is connected through wire 322 with the distributor 323 and the coil 301 through wire 324.

The switch 3|8 is normally closed and is preferably used only in emergencies, so that the engine may be started by towing the car with the sleeve K engaged as will be presently apparent.

The switch R is open at all times except when the vehicle is being driven in one or the other of the forward speeds obtainable by manipulation of the shift clutch vmember Q as will be presently made apparent.

The wire 32| is also connected through wire 325 with a switch L, the latter beinggrounded at 325. The switch L is operated by the clutch pedal 84 and acts to energize the relay N during operation of the pedal 04 to release the clutch C. Any suitable type of switch may be used such as that diagrammatically illustrated in Fig. 24A which comprises an annular elongated conductor 321 slidably engaged in closing the switch by a positioned as shown in grounded by wire 33| while conductor 321 is con-.

nected to the aforesaid wire 325.

The arrangement is such that the switch L is closed prior to unloading of the clutch C. Thus,`

as the pedal 84 is depressed, the first part of the movement to the position 84 takes up the clutch operating clearance during which losty motion interval the clutch pedal moves conductor 328 into electrical contact with the conductor 321 thereby energizing the relay N. Continued movement of the pedal 84 to position 84" effects release of the clutch C while maintaining the switch L closed, conductor 328 sliding along conductor 321.

Because of the difiiculty of diagrammatically showing the valving V and the other parts of the transmission mechanism in the Fig. 24 diagram, these parts have been slightly rearranged and abbreviated in form although functionally operating as in the more detailed showing,

The operation of the whole is as follows.

With the car parked, the transmission D will, of course, be in neutral with the manually shiftable sleeve Q and the automatic shiftable clutch member K positioned as shown in Fig. 9. 'I'he ignition is off at switch 306 and the relay N and solenoid J are de-energized, the valving V being Figs. 15 and 24.

The engine is normally started with the transmission in neutral. As soon as the selector lever |65 is shifted into one of the forward driving positions, switch R will close and the relay N will be energized thus closing the contact 3||, 3| 2 and causing the solenoid J to be energized. Energization of the solenoid J causes the valve stem 236 to be moved to the Fig. 16 position ventpower transmission as a ing the motor M by establishing communication between passage 229 and the interior of the transmission casing by way of passage 333. It may also be noted that at'this time both the high speed and the low speed switches X and Y of the governor controlled mechanism H are closed as shown in Figs. 24 and 25. The clutch member K remains in its rearward released Fig. 9 position.

When the engine starts, the forward rotation of the crankshaft 18 drives the pinion 90 through the uid .coupling B and main clutch C thereby driving the countershaft clutch 91 in its normal backward rotation and causing rotation of the pump P. With the pump P operating, pressure fluid is delivered through passage |31 and thence through passages 230 and 23| into the chamber 235 of the valve V, thereby causing the piston 231 to be moved rearwardly against the spring 238 to uncover the port 242 thus permitting lubricant to be directed through the pipe 245 into the groove 24S-of the slip collar 244 so that as the engine idles, oil under pressure is supplied to the transmission lubricating system. It may be noted that ordinarily the drag or creep effect at the coupling B will cause the runner to drive even with the engine idling, althoughjif desired, means may be employed to prevent drive of the pinion during the time that the engine is idling and the car is stationary. To start in the low or slowest driving speed ratio ordinarily called first speed, the driver depresses clutch pedal 84 to release clutch C and then shifts the manually operable selector lever |65 forwardly to the low range thereby causing the manually shiftable sleeve Q to shift rearwardlyfor blocker synchronizing clutching with the teeth of th'e low speed gear |09. 'I'his shift is facilitated by release of clutch C thereby disconnecting the pinion 90 from the engine A at-coupling B.

Depression of the clutch pedal 84 closes the -switch L, but as the solenoid J is already maintained in energized condition by the action of the switches X and Yin the governor controlled mechanism H, the switch L has no function at this time.

The driver then releases the pedal 84 to engage the clutch C while depressing the accelerator pedal 59 to start the car in first or low speed.

The drive in first is obtained as follows: Pinion 90 drives gear 96 causing rotation of the cluster 91 and gear |06 which in turn drives gear |09 the latter being clutched to the intermediate shaft 93 by the shift member Q. The drive passes from the shaft 93 vand annulus gear |85 to the i to a speed suflicient to cause the governor controlled switch X to open thereby de-'energizing the solenoid J and causing the v'alve V to deliver uid into the motor M, tlie clutch member K will be prevented from shifting forwardly beyond its Fig. 9 position because the blocker 2|0 will lag behind the member K in blocking position.

The drive in first is a non-free wheeling" drive below approximately 10 M. P. H. car speed because within such limits thelow speed governor control switch X remains closed and the solenoid J remains energized thus maintaining motor M vented. Upon coast of the vehicle the driven shaft |03 attempts to overrun the intermediate shaft 93 by automatic release of the overrunning device E; but as the annulus gear .|85 then be-v comes the reaction element of the planetary train, the sun gear is given a forward rotational tendency and the rollers 206' of the overrunning device F lock the member 2|0 to the carrier |88. Thus the ratio on coast in low or first speed is a 1 to 1 ratio and no free-wheeling takes place.

When the car is driven above 10 M. P. H. in

first, this being the normal operation of the car l and being one reason for setting the critical speed of the low speed governor controlled switch in the assumed low car speed, the switch X opens, thereby de-energizing the solenoid J whereupon the stem of the valve V moves from its Fig. 16 posi.- tion to the Fig. 15 position. This causes delivery of the pressure fiuid into passage 229 thence into the motor M whereupon piston 221 and rod 2|8 move forwardly only slightly or until the clutch member K abuts the lugs 2|3 of the blocker member 2|0 whereupon the blocker member prevents further forward shift of the clutch member. It may also he noted that the fluid switch S remains open after piston 221 moves forwardly by reason of the fluid pressure in the chamber forwardly of the piston 264 (Fig. 21) y While the car is being driven in the foregoing condition above 10 M. P. H. in first, the shift from first to second is automatic and operates in response to the driver release of the accelerator pedal 59 sufficiently to slow down the engine speed to the point where the blocker member 2|0 will be rotated forwardly suiciently to unblock forthe drive as described above.

.planetary gearset G and the tailshaft |03 will momentarily become the driving shaft while the intermediate shaft 93 will tend to decrease in' speed due to the slowing down of the motor. Under such conditions the annulus gear will drop off in speed and will become momentarily the reaction element of the planetary train instead of the driving element. Planet carrier |88 which is splined to the shaft |03 at |90 will then begin to drive sun gear |9| in a forward (clockwise) direction, the control sleeve portion |92 overrunning the reaction member |98 through the rollers 20| of the clutch E. The sleeve |92 will then immediately become drivingly locked to the blocker member 2|0 because of the cam 206 which will then wedge the rollers 206 of overrunning clutch F (see Fig. 22) into driving engagement. Blocker member 2|0 will then tend to drive the shaft |03 and will rotate forwardly slightly with respect to said shaft to take up the lost motion incident to the loose splined connection 2|I. This slight forward rotation of the member 2|0 is designed to be just suiiicient to unblock the lugs 2|3 which action will allow said lugs to enter the openings 2|4 of the clutch member K and will allow said member to move forwardly under the action of the spring 222 (Fig. 19) which was previously'loaded by the forward movement of the piston 221 and the rod 2|8, thereby engaging the teeth 203 of the clutch member K with the teeth |93 of the control sleeve |92. At this stage the shaft |03, the blocker 2|0, the sleeve |92, and the slutch member K are all rotating forwardlywith the shaft. 93, thus engagement of the teeth 203 and |93 is accomplished positively and silently.

Opening of the engine throttle will now cause r the engine to be driven forwardly with the planetary gearset G locked up to rotate as a unit thereby giving a 1 to 1 -driving ratio through the gearset, and causingshafts 93 and |03 to rotate at identical speed.

Under certain conditions of operation it may occur that the teeth |93 will be in such position with relation to the teeth 203 that these two sets of teeth will abut and block forward movement of the clutch member K during release of In such case, at the instant the driver opens the throttle to accelerate the vehicle there will be a tendency for the clutch member K to rotate forwardly with relation to the member |92 which latter member will tend to rotate rearwardly due to reaction of the drive through the planetary gearset. Very slight relative movement of these parts will of course unblock the teeth which will slide into mesh under the influence of the pressure of spring 222 thereby establishing direct drive. If desired, either of the teeth 203 and |93 or both sets may be slightly bevelled to facilitate meshing.

During the above described cycle of operation the overrunning rollers 20| and 206' which form parts of clutches E and F respectively will have a definite relation because of the interconnection between cages 201 and 208. In other words, the rollers 206 will always be in non-driving position during the period rollers 20| are locked and roll.- ers 20| will be held in their neutral position during the period of lock-up of the rollers 20B with members |92 and 2|0.

This feature is of paramount importance in the efiicient operation of theA transmission as it prevents an uncontrollable no-back condition which might occur if the car were driven against an obstruction with suiflcient force to spring the bumper thereof. Under such conditions with the transmission in gear, backward thrust would be exerted on the vehicle by the bumper which would tend to turn the tail shaft |03 backwardly and wedge both sets of the overrunning rollers into lock-up position thereby making it impossible for the driver to manipulate the sleeve Q out of mesh because of the frictional load of the teeth of the engaged gears and clutches in the transmission.

With the arrangement just described, such an uncontrollable no-back condition will never occur because of the interconnecting spokes 209 which maintain a definite fixed relationship between the roller cages 201 and 208. When the rollers 20| are in lock-up position the rollers 206' will be held in neutral position by the cage 201 and similarly, when the rollers 206' are in lockup position rollers 20| will be held in neutral by cage 208.

The drive in secondl passes from pinion 90 through gear 96, counter'shaft cluster member 91 and gear |06, thence to gear |09 which is clutched to shaft 93 through sleeve Q, thence to tail shaft |03 through planetary gearset G which is locked up to rotate as a unit and is therefore splined to the shaft |03 at |90' and 204. This drive is a two-way drive, 'sleeve |92 overrunning the reaction member I94 through the intermediary of the rollers 20| and the clutch member K is maintained in engaged position by the oil pressure at motor M which holds rod 2|8 and shift yoke 205 forwardly. The engine is used as a brake during coast in second speed ratio, the car driving the engine approximately twice the speed of the tail shaft |03 for the particular gear size illustrated.

Coasting in second v'speed below l0 M. P. H. causes the low speed governor switch X to close thereby energizing the relay N which in turn energizes the solenoid J and adjusts the valve V from the Fig. position to the Fig. 16 position and vents motor M. However, as the teeth of clutch member K are loaded during coast, the clutch member K will not lmove rearwardly to its released position under the inuence of the spring 224 until the torque through the transmission is reversed by depressing the accelerator pedal to cause the engine to drive the car. When this,takes place, spring 224 acts to move rod 2|8, shift yoke 205 and clutch member K rearwardly as a unit back to the position shown in Figs. 9 and 19 so that the car acceleration under such conditions will automatically take place in low or first speed ratio. Of course, if the car coast in second speed ratio does not go below 10 M. P. H. then the low speed governor switch X remains closed and the acceleration of the car will then take place in second without shifting back to low.

In shifting from second-speed ratio to the high range several different results may be obtained depending for the most part upon the car speed, which different results are controlled by operation of the governor controlled switch X. Incidentally, it is desired to point out that the functioning of the governor switch X is the same in second as in first or low speed ratio because the shaft 213 is driven from the tail shaft |03.

Assuming that the car is driven at a speed below 10 M. P. H. in second so that the switch X closes speed ratio.

to energize solenoid J, then when the driver depresses clutch pedal 84 (switch L being without function in this instance as the solenoid'is already energized) to release the main clutch C, he may then move the manual selector lever |65 rearwardly to the high range position to cause the shift sleeve Q to move forwardly and effect a blocker synchronizing shift to clutch with teeth |0| of gear 90 whereby this gear is directly drivingly connected with the intermediate shaft 93 'through the sleeve Q and the hub |04. The driver then releases the clutch pedal 84 and depresses the accelerator pedal to drive the car in third rIfhe clutch member K will be released in this instance becausev the switch X maintains the solenoid'J energized and a reversal of torque occurs whenthe clutchC is released to unload the teeth ofsleeve Q. The drive in third takes place from the main pinion to the shaft 93 through sleeve Q and hub |04 thence to the shaft |03 through the -annulus gear |85, planet gears |86 and planet carrier |89, the sun gear |9| being locked to the casing |80 through the intermediary of the overrunning device E and the reaction taking member |94.

If, on the other hand, the car is driven above 10 M. P. H. in second then the low speed switch X will remain open and the solenoid will remain cle-energized to maintain the valve'V in its Fig. 15

condition so that pressure fluid will be supplied to the motor M thereby holding clutch member K in forward position. In shifting to the high range under these conditions, the driver presses the clutch pedal 84 which rst closes switch L to energize relay N and solenoid J and vent motor M and then releases main clutch C. The driver then shifts the selector lever |65 rearwardly to the high range as before, to clutch sleeve Q with gear 90 and under these conditions the shift to high range will ybe made under one of the following conditions:

Firstly, as the driver releases the clutch pedal 84 while maintaining the accelerator 59 depressed so that the throttle is opened prior to engagement of main clutchC then third speed is obtained because the blocker 2|0 will lag and block clutch member K prior to de-energizing solenoid J as switch L opens to restore the valve V to the Fig. 15 position of supplying pressure fluid to the motor M. Under such conditions the car will be driven in third speed ratio with the clutch member K blocked against forward movement as shown in Fig. 9.

Secondly, if the driver releases the clutch pedal 84 prior to depressing the accelerator pedal 59 then the third speed drive is also obtained when the accelerator pedal is depressed because, although in engaging main clutch C the switch L opens to de-energize solenoid J and permits the clutch member K to move forwardly, the blocker 2|0 lags behind the shaft I 03 at this time and thus be blocked from engagement.

Under all of the above conditions, the switch R is opened for an instant when the rail ||3 passes through neutral, thus opening the relay circuit. Ordinarily this will have no effect upon the position of the parts because ofthe short period within which switch R is opened and closed.

When driving in third speed ratio above 10 M. P. H., the switch X is open and the solenoid J is de-energized, therefore direct drive will automatically be obtained when the accelerator pedal is released to accommodate synchronous clutching of the clutchmember K. Under such condi- 

